1. Field of the Invention
The present invention relates to a system for performing an operation related to a circuit substrate such as a printed circuit board, for example, mounting circuit components such as electric-circuit or electronic-circuit components on the circuit substrate, or applying an adhesive to the circuits substrate.
2. Related Art Statement
There is known a circuit-substrate-related-operation performing system which includes a conveyor for conveying a circuit substrate (xe2x80x9cCSxe2x80x9d) and positioning and supporting the CS, and an operation performing device for performing an operation related to the CS positioned and supported by the conveyor. For example, there is known a system of this sort which includes (a) a main conveyor which conveys a CS and positions and supports the CS, (b) an operation performing device which performs an operation for the CS positioned and supported by the conveyor, (c) a carry-in conveyor which conveys the CS toward the main conveyor and hands over it thereto, and (d) a carry-out conveyor which receives the CS from the main conveyor and conveys it away from therefrom.
As a system of this sort, there is known a circuit-component (xe2x80x9cCCxe2x80x9d) mounting system for mounting CCs on a CS. This system includes (a) two CS conveying lines which are arranged in parallel with each other and each of which includes a carry-in conveyor, a main conveyor, and a carry-out conveyor arranged in series with one another, and (b) a CC mounting device which mounts CCs on a CS positioned and supported by each of the two main conveyors. More specifically described, while the CC mounting device mounts CCs on a CS positioned and supported by one of the main conveyors, a CS which is positioned and supported by the other main conveyor and on which CCs have been mounted is carried out therefrom by the carry-out conveyor, and another CS is carried in onto the other main conveyor and is positioned and supported thereby.
In the above CC mounting system, the CC mounting device can start mounting the CCs on the CS positioned and supported by the other main conveyor, immediately after it finishes mounting the CCs on the CS positioned and supported by the one main conveyor. Thus, it needs substantially no time to change two CSs with each other, which leads to improving the efficiency of mounting of CCs.
However, the above CC mounting system has the two carry-in conveyors and the two carry-out conveyors. Meanwhile, an upstream-side device is provided on an upstream side of the CC mounting system in a direction of conveying of CSs, and a downstream-side device is provided on a downstream side of the CC mounting system. The upstream-side device hands over a CS to the CC mounting system, and the downstream-side device receives the CS from the CC mounting system. The upstream-side device may be a CS supplying device, another CC mounting system, or an applying system which applies an adhesive or a solder paste to CSs. The downstream-side device may be another CC mounting system, an adhesive curing furnace which cures or hardens the adhesive temporarily fixing the CCs to the CS, a solder reflowing furnace which reflows or melts the solder for electrically connecting the CCs to the CS. Generally, the upstream-side device has only a single CS-hand-over portion, and the downstream-side device has only a single CS-receive portion. Accordingly, a CS receiving and distributing device is needed which receives CSs from the CS-hand-over portion of the upstream-side device and distributes the CS to the two carry-in conveyors, and a CS collecting and handing-over device is needed which collects the CS from the two carry-out conveyors and hands over the CS to the CS-receive portion of the downstream-side device. This leads to complicating the construction of the CC mounting system, thereby increasing the production cost of the same. This problem will also occur to other systems which include operation performing devices other than the CC mounting device.
It is therefore an object of the present invention to provide a circuit-substrate-related-operation performing system which includes a plurality of main conveyors, performs a circuit-substrate-related operation with improved efficiency, and enjoys a simple construction.
The present invention provides a circuit-substrate-related-operation performing system which has one or more of the technical features which are described below in respective paragraphs given parenthesized sequential numbers (1) to (28). Any technical feature which includes another technical feature shall do so by referring, at the beginning, to the parenthesized sequential number given to that technical feature. Thus, two or more of the following technical features may be combined, if appropriate. Each technical feature may be accompanied by a supplemental explanation, as needed.
(1) According to a first feature of the present invention, there is provided a system for performing an operation for a circuit substrate, comprising a plurality of main conveyor each of which conveys, positions, and supports a circuit substrate, the plurality of main conveyors being arranged in a direction perpendicular to a circuit-substrate conveying direction in which the each main conveyor conveys the circuit substrate; an operation performing device which performs at least one operation for the circuit substrate positioned and supported by the each main conveyor; at least one of (a) a carry-in conveyor which conveys the circuit substrate to the each main conveyor and loads the circuit substrate thereon, and (b) a carry-out conveyor which loads the circuit substrate off the each main conveyor and conveys the circuit substrate away therefrom; and a conveyor shifting device which selectively shifts the at least one of the carry-in conveyor and the carry-out conveyor to one of a plurality of shift positions at each of which the one conveyor is aligned with a corresponding one of the main conveyors. In the case where the present operation performing system includes the carry-in conveyor and the conveyor shifting device shifts the carry-in conveyor, the carry-in conveyor can receive a CS at a desired one of the plurality of shift positions thereof, and can hand over the CS to a desired one of the main conveyors at a corresponding one of the shift positions which may be the same as, or different from, the desired shift position. Since the carry-in conveyor is shifted by the conveyor shifting device, it can receive a CS at each of its shift positions and can hand over the CS to each of the main conveyors at a corresponding one of the shift positions. Meanwhile, in the case where the present operation performing system includes the carry-out conveyor and the conveyor shifting device shifts the carry-out conveyor, the carry-out conveyor can receive a CS from each of the main conveyors at a corresponding one of the plurality of shift positions thereof, and can carry out the CS at a desired one of the shift positions which may be the same as, or different from, the one shift position where the carry-out conveyor receives the CS from the each main conveyor. Thus, the present system does not need more than one carry-in conveyor or more than one carry-out conveyor in contrast to the conventional system. In addition, the present system does not need any device for distributing CSs to the plurality of main conveyors, or any device for collecting CSs from the plurality of main conveyors. Thus, the present system includes the plurality of main conveyors, needs substantially no time for changing CSs with each other, performs the operation with high efficiency, and enjoys a simple construction. In the case where the present system includes the carry-in conveyor and an upstream-side device for handing over CSs to the carry-in conveyor, the carry-in conveyor can receive the CSs at a desired one of the plurality of shift positions thereof. Therefore, even in the case where the upstream-side device is designed such that it can hand over CSs at a single predetermined position only, the upstream-side device can easily connected to the present system. This is also true with the case where the present system includes the carry-out conveyor and a downstream-side device for receiving CSs from the carry-out conveyor, and the case where the present system includes both the carry-in conveyor and the carry-out conveyor and both an upstream-side device for handing over CSs to the carry-in conveyor and a downstream-side device for receiving CSs from the carry-out conveyor. The main conveyors may not be so long because they are just required to have a length sufficient to position and support a CS, whereas the distance by which a CS is conveyed by the carry-in conveyor or the carry-out conveyor for being carried in onto, or carried out from, each main conveyor may be considerably long. Accordingly, the carry-in conveyor and/or the carry-out conveyor may be considerably long. However, since the present system employs the single carry-in conveyor and/or the single carry-out conveyor, it can be produced at reduced cost, as compared with the case where the same number of carry-in and/or carry-out conveyors as that of the main conveyors are employed, though the present system additionally includes the conveyor shifting device or devices for shifting the carry-in conveyor and/or the carry-out conveyor. In the case where each CS has its identification such as a bar code, the present system is equipped with just a single CS identifying device which identifies the sort of each CS by recognizing the identification thereof and which is provided on the single carry-in conveyor. In this case, the present system does not need more than one CS identifying device, which leads to reducing the cost of CS identification. If the carry-in conveyor is designed such that it can receive CSs at a single predetermined shift position only, the single CS identifying device may be provided at that shift position. The operation performing device may be one of various devices including a CC mounting device, a CS processing device, a circuit testing device, and a high-viscosity-fluid applying device such as a screen printing machine and an adhesive dispenser. In any case, the present system can enjoy the above-indicated advantages. The shorter the cycle time between the beginning and the end of one operation or a series of operations which is or are performed for each CS is, the greater the ratio of the time needed for changing CSs with each other to the cycle time is, that is, the greater the advantage that the plurality of main conveyors are employed for reducing the time needed for changing CSs with each other to substantially zero is. Thus, the present invention is very advantageous for the devices, such as the circuit testing device and the high-viscosity-fluid applying device, which have a considerably short operation-cycle time. In particular, the high-viscosity-fluid applying device can store a high-viscosity fluid in an amount that can be successively applied to a plurality of CSs, and can successively apply the fluid to CSs except each time period during which it is supplied with the fluid from a fluid supplying device. That is, the operation of the fluid applying device is not interrupted by the changing of CSs and accordingly can be done with high efficiency. Even in the case where the present system employs an operation performing device which has a long operation-cycle time and therefore has a small ratio of the CS-changing time to the operation-cycle time, the present system can enjoy a great advantage that the CS-changing time is reduced to substantially zero and accordingly its substantial availability factor is improved, if the operation performing device is an expensive device such as a CC mounting device. The present system may employ one, two, or more CC mounting devices. The or each CC mounting device may hold one or more component holders. The present system may employ one, two, or more operation performing devices other than the CC mounting device or devices. The present system may employ a plurality of operation performing devices of a same sort or of different sorts. The present operation performing system can enjoy the above-indicated advantages not only in the case where it employs both the carry-in and carry-out conveyors but also in the case where it employs either the carry-in or carry-out conveyor. For example, the present system may be a xe2x80x9clinexe2x80x9d system which includes a plurality of operation performing devices each of which performs a certain operation for a CS and which are arranged in series with each other. In this case, at the downstream-side end of the line system, a robot or an operator can take the CSs directly from the main conveyors to store them in a storing device such as a stocking device. Thus, the line system does not need any carry-out conveyor, and employs a carry-in conveyor only. However, since the single carry-in conveyor can selectively hand over a CS to each of the plurality of main conveyors, the line system can enjoy the above-indicated advantages of the present invention. Also, at the upstream-side end of the line system, a robot or an operator can place the CSs directly on the main conveyors, or a CS supplying device may be provided which has a plurality of CS-hand-over portions for handing over the CSs to the plurality of main conveyors, respectively. In this case, the line system does not need any carry-in conveyor, and employs a carry-out conveyor only. However, since the single carry-out conveyor can selectively receive a CS from each of the plurality of main conveyors, the line system can enjoys the above-indicated advantages of the present invention. The present system may include two, three, or more main conveyors. In the case where the present system employs three or more main conveyors, the carry-in and/or carry-out conveyors have three or more shift positions. In the latter case, the conveyor shifting device may comprise, as a drive source thereof, a combination of a plurality of fluid-pressure-operated cylinder devices, or an electric motor such as a servomotor, which selectively shifts the carry-in or carry-out conveyor to one of the three or more shift positions thereof. The servomotor as the drive source of the conveyor shifting device can easily move and stop the carry-in or carry-out conveyor to and at a position or positions different from the three or more shift positions thereof.
(2) According to a second feature of the present invention which includes the first feature (1), the operation performing device comprises at least one circuit-component mounting device which mounts at least one circuit component on the circuit substrate positioned and supported by the each main conveyor. Immediately after the CC mounting device finishes mounting CCs on a CS positioned and supported by one of the plurality of main conveyors, the CC mounting device can start mounting CCs on a waiting CS positioned and supported by another or the other main conveyor. Thus, the CC mounting device can mount CCs with high efficiency. Since the single CC mounting device can mount CCs on a CS on each of the main conveyors, the present system does not need another CC mounting device. However, the present system may employ a plurality of CC mounting devices. In the latter case, while one CC mounting device takes CCs from a CC supplying device, the other CC mounting device can mount CCs on a CS. Thus, the CC mounting operation is not interrupted by the CC taking operation, which leads to improving the efficiency of mounting of CCs. The CC mounting device may be one of various devices. For example, the CC mounting device may be provided by a device including a plurality of component holders which is revolved around a common axis line and is sequentially positioned at a predetermined operative position and which is moved between a CC supplying device and the main conveyors, for receiving CCs from the supplying device and mounting the CCs on CSs on the main conveyors; or a device including a single component holder which is moved to desired positions in a component-holder moving plane facing a CC supplying device and CSs, for receiving CCs from the supplying device and mounting the CCs on the CSs.
(3) According to a third feature of the present invention which includes the first feature (1), the plurality of main conveyors comprises two main conveyors, wherein the system further comprises two circuit-component supplying devices which are provided outside the two main conveyors such that the two main conveyors are positioned between the two circuit-component supplying devices, and wherein the operation performing device comprises two circuit-component mounting devices each of which receives at least one circuit component from a corresponding one of the two circuit-component supplying devices, conveys the one circuit component to above each of the two main conveyors, and mounts the one circuit component on the circuit substrate positioned and supported by the each of the two main conveyors. In the present system, the two CC mounting devices cooperate with each other to mount CCs on a CS positioned and supported by each of the two main conveyors, for providing a circuit on the CS. It is particularly preferred that the present system be operated such that while one CC mounting device mounts CCs on a CS, the other CC mounting device receives CCs from a corresponding one of the two CC supplying devices and such that after the one CC mounting device finishes mounting the CCs on the CS, the other CC mounting device starts mounting the CCs on the CS in place of the one CC mounting device. If the present system employs a single CC mounting device only, no CC can be mounted on a CS after the single mounting device finishes mounting all CCs on the CS and before it starts mounting CCs on the CS after receiving the CCs from a CC supplying device. This is a waste of time. On the other hand, if the present system employs the two CC mounting devices which alternately mount CCs on a CS, it can mount the CCs on the CS without any waste of time. Thus, the present system can mount CCs on CSs with improved efficiency owing to not only the advantage that substantially no time is needed for changing two CSs with each other but also the advantage that the two CC mounting devices alternately mount CCs on each CS. However, it is not essentially required that the two CC mounting devices alternately mount CCs on each CS. For example, in the case where the present system employs a single CC mounting device only, the present system may employ two CC supplying devices each of which is of a considerably small size and supplies various sorts of CCs to the CC mounting device. In the last case, the present system can provide a circuit which needs various sorts of CS, while preventing an excessive increase of the distance of movement of the CC mounting device.
(4) According to a fourth feature of the present invention which includes the third feature (3), the each circuit-component mounting device comprises a mounting head which includes a plurality of component holders which are revolvable around a common axis line, and a component-holder positioning device which sequentially positions the component holders at at least one operative position predetermined on a locus of the revolution of the component holders; and a mounting-head moving device which moves the mounting head to a desired position in a mounting-head moving plane which faces the one circuit-component supplying device and the two main conveyors. In the present system, each of the CC mounting devices receives, each time, a plurality of CCs from a corresponding one of the CC supplying devices, and mounts all the CCs on a CS. In contrast, if each CC mounting device includes a single component holder only, the CC mounting device is moved between the corresponding CC supplying device and the CS each time the single component holder receives and mounts a single CC. Thus, the present system can mount CCs on a CS with a reduced number of movements of each CC mounting device between the corresponding CC supplying device and the CS, which leads to improving the efficiency of mounting of CCs. When the plurality of component holders are sequentially positioned at the operative position predetermined con the locus of revolution thereof, each for receiving a CC, each of the component holders is positioned at the operative position by a small angle of revolution thereof. In addition, the positioning of each mounting head relative to the corresponding CC supplying device can easily be done by aligning the operative position of the mounting head with a portion of the CC supplying device which supplies the next CC to the mounting head. Thus, if CCs are provided at appropriate positions on each CC supplying device, the amount of relative movement between the CC supplying device and the corresponding mounting head can be very small, and accordingly the time needed for revolving each component holder and moving each mounting head can be significantly shorter than the time needed for moving each component holder between the corresponding CC supplying device and the CS. Thus, the present system can receive CCs with high efficiency. This is also true when CCs are mounted on a CS, and accordingly the present system can mount CCs with high efficiency. The component-holder positioning device also functions as a component-holder revolving device which revolves the plurality of component holders for sequentially positioning them at the operative position. Each of the CC mounting devices may be one which includes (a) an X-Y robot and (b) an index-type CC mounting head which is conventionally employed in an index-type CC mounting device and which is moved by the X-Y robot. Thus, each CC mounting device enjoys the same CC-mounting efficiency as that of the index-type CC mounting device. In addition, in the case where two CC mounting devices alternately receive CCs, and alternately mount the CCs on a CS, the CC-mounting-operation cycle time of the present system at which each CC is mounted on a CS can be shortened to the same degree as that to which the index-type CC mounting device shortens its CC-mounting-operation cycle time. However, since the index-type CC mounting head transfers, by the rotation thereof, a CC from a CC supplying device to above a CS, it is difficult to decrease the diameter of locus of revolution of the component holders held by the index-type mounting head and accordingly it is difficult to increase the speed of rotation of the index-type mounting head. Contrary to that, the present system need not revolve the component holders along so great a circle and accordingly can revolve them at high speed. In addition, since each mounting head can be positioned, by the movement thereof, relative to the corresponding CC supplying device or the CS, the CC supplying device may not be a CC supplying table including a number of component feeders and a movable table which is movable while supporting the feeders. In addition, the present system does not need any CS supporting device which is movable, while supporting a CS, for moving each of CC-mount places on the CS to a component mounting position of each CC mounting device. A large space would be needed to allow the CC supplying table and the CC supporting device to move relative to each CC mounting device. In particular, in the case where large-size CSs are employed, or in the case where various sorts of CCs are mounted on a CS, a large-size CC supplying table and a large-size CS supporting device would be needed, but a larger space would be needed to allow the respective movements of those elements. In contrast, the present system can be provided in a small space. Moreover, since the index-type CC mounting device cannot quickly accelerate or decelerate a large-size CC supplying table and a large-size CS supporting device, it cannot reduce the CC-mounting-operation cycle time. In contrast, the present system is free from this problem. Each CC mounting device is operated such that the plurality of component holders are sequentially positioned at the operative position by the revolution thereof and the mounting head is moved to desired positions in the mounting-head moving plane by the mounting-head moving device. This CC mounting device enjoys a high CC-mounting efficiency, but is somewhat expensive. Thus, if the CS-changing time of the present system is reduced to substantially zero, so that the CC mounting devices can be operated without needing any pause or break, the present system can be highly cost-effective and can particularly effectively enjoy the above-indicated advantages of the operation performing system according to the first feature (1). The mounting-head moving plane may be a horizontal plane or a plane inclined with respect to a horizontal plane, and may be defined in one of various manners, e.g., may be defined by an X-Y coordinate system, a polar coordinate system, or the like. In the case where the CS and the CC supplying devices are provided while taking respective attitudes inclined with respect to a horizontal plane, each of the mounting heads is moved in the mounting-head moving plane which is inclined with respect to the horizontal plane, for taking CCs from the inclined CC supplying devices and mounting the CCs on the inclined CS. In the case where the moving plane is defined by the X-Y coordinate system, the mounting-head moving device may be provided by, e.g., an X-Y robot. An operative position where each component holder receives a CC may be the same as, or be different from, an operative position where the component holder mounts the CC on the CS. Each component holder may be provided by one of various holders such as a component sucker which sucks and holds a CC by applying a negative pressure thereto, or a component chuck including a plurality of grasping members and a grasping-member opening and closing device for symmetrically opening and closing the grasping members with each other.
(5) According to a fifth feature of the present invention which includes any one of the first to fourth features (1) to (4), the operation performing system comprises both (a) the carry-in conveyor provided on an upstream side of the main conveyors in the circuit-substrate conveying direction and (b) the carry-out conveyor provided on a downstream side of the main conveyors in the circuit-substrate conveying direction, wherein the system further comprises an upstream-side device which is provided in alignment with a reference position as one of the plurality of shift positions of the carry-in conveyor and which hands over the circuit substrate to the carry-in conveyor, and a downstream-side device which is provided in alignment with a reference position as one of the plurality of shift positions of the carry-out conveyor and which receives the circuit substrate from the carry-out conveyor. The upstream-side or downstream-side device may be one which just hands over a CS to the carry-in conveyor or one which just receives a CS from the carry-out conveyor, or one which performs some operation for a CS, e.g., applies an adhesive to a CS or hardens an adhesive on a CS. The carry-in conveyor can receive a CS at any one of the plurality of shift positions thereof, and the carry-out conveyor can hand over a CS at any one of the plurality of shift positions thereof. Thus, even in the case where the upstream-side and downstream-side devices have only a single CS-hand-over position and only a single CS-receive position in the directions of shifting of the carry-in and carry-out conveyors, respectively, the carry-in and carry-out conveyors can receive, without any problems, CSs from the upstream-side device and hand over CSs to the downstream-side device, respectively, if the upstream-side and downstream-side devices are connected to the carry-in and carry-out conveyors and the main conveyors, such that the CS-hand-over position of the upstream-side device is aligned with a reference position as one of the shift positions of the carry-in conveyor and the CS-receive position of the downstream-side device is aligned with a reference position as one of the shift positions of the carry-out conveyor.
(6) According to a sixth feature of the present invention which includes any one of the first to fifth features (1) to (5), the at least one of the carry-in conveyor and the carry-out conveyor comprises a pair of side frames including at least one movable side frame which is movable toward, and away from, the other side frame, wherein the system further comprises a width changing device which changes a circuit-substrate conveying width defined by the pair of side frames of the at least one conveyor, by moving the movable side frame thereof relative to the other side frame thereof, and wherein the width changing device comprises a drive shaft which is provided corresponding to the at least one conveyor and which extends over the plurality of shift positions thereof; a driven rotatable member which is held by the at least one conveyor such that the driven rotatable member is rotatable about an axis line thereof, and is not movable in an axial direction thereof, relative to the at least one conveyor and which is engaged with the drive shaft such that the driven rotatable member is not rotatable about the axis line thereof, and is movable in the axial direction thereof, relative to the drive shaft; and a motion converting device which converts the rotation of the driven rotatable member into the movement of the movable side frame of the at least one conveyor. In the present system, even if a shiftable conveyor as one of the carry-in and carry-out conveyors is shifted, the drive shaft cannot be moved in the axial direction thereof. In addition, the driven rotatable member provided for the shiftable conveyor can be rotated irrespective of the current shift position of the shiftable conveyor. Thus, a handle which is manually rotatable by an operator for applying its rotary drive force to the drive shaft directly or indirectly via a rotation transmitting device, may be provided at a fixed position, which leads to facilitating the CS-conveying-width-changing operation. In addition, in the case where the drive shaft is driven by a drive source such as an electric motor, the drive source may be provided at a fixed position where the rotation of the drive source may be transmitted to the drive shaft via a simple rotation transmitting device, which leads to reducing the production cost of the present system. In the case where the present system comprises both the carry-in and carry-out conveyors and the two side frames of each of the carry-in and carry-out conveyors comprise at least one movable frame, the respective CS conveying widths of the carry-in and carry-out conveyors can simultaneously be changed by transmitting the rotary drive force of the handle or the drive source to respective drive shafts provided for the carry-in conveyor and the carry-out conveyor, via a common rotation transmitting device or respective exclusive rotation transmitting devices.
(7) According to a seventh feature of the present invention which includes any one of the first to fourth and sixth features (1) to (4) and (6), the operation performing system comprises both (a) the carry-in conveyor provided on an upstream side of the main conveyors in the circuit-substrate conveying direction and (b) the carry-out conveyor provided on a downstream side of the main conveyors in the circuit-substrate conveying direction. If the respective CS-conveying directions of the carry-in and carry-out conveyors are reversed in addition to those of the main conveyors, then they function as the carry-out and carry-in conveyors, respectively.
(8) According to an eighth feature of the present invention, there is provided a system comprising at least two subsystems, each according to the seventh feature (7), which are arranged in series with each other, wherein the at least two subsystems comprise a first subsystem comprising the main conveyors as first main conveyors, the operation performing device as a first operation performing device, the carry-in conveyor as a first carry-in conveyor, the carry-out conveyor as a first carry-out conveyor, and the conveyor shifting device as a first conveyor shifting device, and a second subsystem comprising a plurality of second main conveyors each of which conveys, positions, and supports a circuit substrate, the plurality of second main conveyors being arranged in the direction perpendicular to the circuit-substrate conveying direction; a second operation performing device which performs at least one operation for the circuit substrate positioned and supported by the each second main conveyor; a second carry-in conveyor which is provided on an upstream side of the second main conveyors in the circuit-substrate conveying direction and which conveys the circuit substrate to the each second main conveyor and loads the circuit substrate thereon; a second carry-out conveyor which is provided on a downstream side of the second main conveyors in the circuit-substrate conveying direction and which loads the circuit substrate off the each second main conveyor and conveys the circuit substrate away therefrom; and a second conveyor shifting device which selectively shifts each of the carry-in conveyor and the carry-out conveyor to one of a plurality of shift positions at each of which the each conveyor is aligned with a corresponding one of the second main conveyors. In the present system, the carry-out conveyor of the upstream-side subsystem hands over CSs to the carry-in conveyor of the downstream-side subsystem. Each of the carry-out conveyor and the carry-in conveyor can be selectively shifted to one of the plurality of shift positions thereof, so that the carry-out conveyor being positioned at a desired one of its shift positions can hand over a CS to the carry-in conveyor being positioned at a desired one of its shift positions. Thus, it is not required that the carry-out conveyor be positioned at a predetermined one of its shift positions for handing over a CS or that the carry-in conveyor be positioned at a predetermined one of its shift positions for receiving the CS. That is, the carry-out conveyor can hand over a CS at one of its shift positions, and/or the carry-in conveyor can receive the CS at one of its shift positions, which position or positions can be selected depending upon the sorts of the respective operations performed by the first and second operation performing devices and/or the degree of progress of those operations. Thus, the present system enjoys improved degree of freedom.
(9) According to a ninth feature of the present invention which includes any one of the first to fourth and sixth features (1) to (4) and (6), the operation performing system comprises (a) the carry-in conveyor and (b) the carry-out conveyor which comprise a carry-in and carry-out conveyor which is provided on an upstream side of the main conveyors in the circuit-substrate conveying direction. The carry-in and carry-out conveyor can convey CSs in both a forward direction and a backward direction. When it conveys CSs in the forward direction, it functions as a carry-in conveyor; and when it conveys CSs in the backward direction, it functions as a carry-out conveyor. Each of the main conveyors convey CSs in both a forward direction and a backward direction. The present system is particularly advantageous in a special case where a CS must be carried out to the same side as that from which the CS is carried in.
(10) According to a tenth feature of the present invention which includes any one of the first to eighth features (1) to (8), the operation performing system comprises both (a) the carry-in conveyor provided on an upstream side of the main conveyors in the circuit-substrate conveying direction and (b) the carry-out conveyor provided on a downstream side of the main conveyors in the circuit-substrate conveying direction, wherein the conveyor shifting device comprises a carry-in-conveyor shifting device which shifts the carry-in conveyor, independent of the carry-out conveyor, and a carry-out-conveyor shifting device which shifts the carry-out conveyor, independent of the carry-in conveyor. Alternatively, it is possible to employ the conveyor shifting device which simultaneously shifts both the carry-in and carry-out conveyors. However, if the carry-in and carry-out conveyors can be shifted independent of each other, the present system can enjoy improved degree of freedom.
(11) According to an eleventh feature of the present invention which includes any one of the first to tenth features (1) to (10), the conveyor shifting device comprises a conveyor support member which supports the at least one of the carry-in conveyor and the carry-out conveyor, and a fluid-pressure-operated cylinder device which shifts the conveyor support member. Since the fluid-pressure-operated cylinder device is employed, the conveyor shifting device which can quickly shift the carry-in and/or carry-out conveyors can be produced at low cost.
(12) According to a twelfth feature of the present invention which includes the eleventh feature (11), the fluid-pressure-operated cylinder device comprises a rodless cylinder device which extends over the shift positions of the at least one of the carry-in conveyor and the carry-out conveyor. The conveyor shifting device which employs the rodless cylinder device enjoys a simpler construction than a conveyor shifting device which employs a fluid-pressure-operated cylinder having a piston rod.
(13) According to a thirteenth feature of the present invention which includes any one of the first to tenth features (1) to (10), the conveyor shifting device comprises a conveyor support member which supports the at least one of the carry-in conveyor and the carry-out conveyor, and a drive device including an electric motor which shifts the conveyor support member. The electric motor may be a rotary motor, or a linear motor. The rotary motor may be a servomotor or a stepper motor which can be accurately controlled with respect to its rotation angle or position. The rotary motor linear moves the conveyor support member via, e.g., a motion converting device including a threaded shaft and a nut.
(14) According to a fourteenth feature of the present invention which includes any one of the first to thirteenth features (1) to (13), the conveyor shifting device comprises a wide-range conveyor shifting device which moves the at least one of the carry-in conveyor and the carry-out conveyor within a range wider than a range whose opposite ends correspond to two end shift positions of the at least one conveyor, respectively, which correspond to two end main conveyors, respectively. In the case where a shiftable conveyor as at least one of the carry-in and carry-out conveyors is just required to be aligned with each of the plurality of main conveyors, it is only required that the shiftable conveyor be moved within the first range whose opposite ends correspond to the two end shift positions out of all the shift positions of the shiftable conveyor, respectively, which correspond to the two end main conveyors out of all the main conveyors, respectively. However, in the case where the shiftable conveyor is movable within a second range wider than the first range, a device which is arranged in series with the present system can enjoy improved degree of freedom with respect to the position of provision of its CS-hand-over position or CS-receive position, and a xe2x80x9clinexe2x80x9d system including the present system and the above device can enjoy improved degree of freedom of its construction. For example, the present system can employ a plurality of devices such that those devices are arranged in parallel with each other on at least one of the upstream and downstream sides of the carry-in and carry-out conveyors and the main conveyors, and are connected to those conveyors.
(15) According to a fifteenth feature of the present invention which includes any one of the first to fourteenth features (1) to (14), each of the main conveyors comprises a circuit-substrate positioning and supporting device which positions and supports the circuit substrate at a position away from a circuit-substrate conveying plane in which the each main conveyor conveys the circuit substrate. The circuit-substrate positioning and supporting device can surely position and support the CS.
(16) According to a sixteenth feature of the present invention which includes the fifteenth feature (15), each of the main conveyors comprises at least one conveyor belt which supports and conveys the circuit substrate, and the main conveyors comprise a common belt-driving device which simultaneously moves the conveyor belts of the main conveyors. Since the circuit-substrate positioning and supporting device positions and supports the CS at a position away from the CS conveying plane, the CS for which the operation is being performed is not moved even if the respective conveyor belts of the main conveyors are simultaneously moved. In addition, since the common belt-driving device is employed, the present system can be produced at low cost.
(17) According to a seventeenth feature of the present invention which includes any one of the fifth, seventh, eighth, and tenth to sixteenth features (5), (7), (8), and (10) to (16), each of the main conveyors, the carry-in conveyor, and the carry-out conveyors comprises a pair of side frames including at least one movable side frame which is movable toward, and away from, the other side frame, and wherein the system further comprises a width changing device which simultaneously changes a circuit-substrate conveying width defined by the pair of side frames of the each of the main conveyors, the carry-in conveyor, and the carry-out conveyor, by moving the movable side frame of the each conveyor relative to the other side frame thereof.
(18) According to an eighteenth feature of the present invention which includes the seventeenth feature (17), the width changing device comprises a carry-in-conveyor-side drive shaft which is provided corresponding to the carry-in conveyor and which extends over at least the shift positions thereof; a carry-out-conveyor-side drive shaft which is provided corresponding to the carry-out conveyor and which extends over at least the shift positions thereof; a carry-in-conveyor-side driven rotatable member which is held by the carry-in conveyor such that the carry-in-conveyor-side driven rotatable member is rotatable about an axis line thereof, and is not movable in an axial direction thereof, relative to the carry-in conveyor and which is engaged with the carry-in-conveyor-side drive shaft such that the carry-in-conveyor-side driven rotatable member is not rotatable about the axis line thereof, and is movable in the axial direction thereof, relative to the carry-in-conveyor-side drive shaft; a carry-out-conveyor-side driven rotatable member which is held by the carry-out conveyor such that the carry-out-conveyor-side driven rotatable member is rotatable about an axis line thereof, and is not movable in an axial direction thereof, relative to the carry-out conveyor and which is engaged with the carry-out-conveyor-side drive shaft such that the carry-out-conveyor-side driven rotatable member is not rotatable about the axis line thereof, and is movable in the axial direction thereof, relative to the carry-out-conveyor-side drive shaft; a carry-in-conveyor-side motion converting device which converts the rotation of the carry-in-conveyor-side driven rotatable member into the movement of the movable side frame of the carry-in conveyor; and a carry-out-conveyor-side motion converting device which converts the rotation of the carry-out-conveyor-side driven rotatable member into the movement of the movable side frame of the carry-out conveyor. Even if the carry-in or carry-out conveyor is shifted, the driven rotatable member of the carry-in or carry-out conveyor remains engaged with the corresponding drive shaft. Thus, the CS conveying widths of the carry-in and carry-out conveyors can be changed by the rotation of the driven rotatable members thereof, irrespective of which shift positions are currently taken by the conveyors, respectively, or irrespective of whether the respective current shift positions of the conveyors are aligned with each other or not. That is, the carry-in and carry-out conveyors can be shifted independent of each other, although their CS conveying widths are changed simultaneously with each other. Since the carry-in and carry-out conveyors are not required to be moved to any positions for changing their CS conveying widths, the CS-conveying-width changing operation can be more easily done in a shorter time. Each of the two motion converting devices may be provided by (a) a threaded shaft which is supported by a member supporting the corresponding movable side frame such that the movable side frame is movable and which is rotatable about an axis line thereof parallel to a direction in which the movable side frame is moved relative to the other side frame, and is not movable in the axial direction thereof, and (b) a nut which is attached to the movable side frame such that the nut is not rotatable about an axis line thereof, and is not movable in the axial direction thereof, relative to the movable side frame, and which is threadedly engaged with the threaded shaft. In the case where the two side frames of each of the carry-in and carry-out conveyors are movable relative to each other, the threaded shaft of each of the two motion converting devices may be one which includes a first and a second threaded portion which are threaded in different or opposite directions, respectively. In the latter case, if the first threaded portion is threadedly engaged with a first nut fixed to one of the movable side frames, and the second threaded portion is threadedly engaged with a second nut fixed to the other movable side frame, the pair of movable side frames are symmetrically moved toward, and away from, each other, by the rotation of the threaded shaft, for changing the CS conveying width of a corresponding one of the carry-in and carry-out conveyors.
(19) According to a nineteenth feature of the present invention which includes the eighteenth feature (18), the width changing device further comprises a width-changing-rotation producing device; and a rotation transmitting device which transmits the rotation of the width-changing-rotation producing device to the carry-in-conveyor-side drive shaft and the carry-out-conveyor-side drive shaft. In the present system, the changing of the CS conveying widths of the carry-in and carry-out conveyors is done using the width changing rotation produced by the width-changing-rotation producing device. If the present system further comprises a control device for automatically controlling the producing device, the present system can automatically change the CS conveying widths of the conveyors. It is possible to employ two exclusive width-changing-rotation producing devices for driving the two drive shafts, respectively, and a control device for controlling the two producing devices such that the two driven shafts are rotated in synchronism with each other. In the latter case, the CS conveying widths of the carry-in and carry-out conveyors are simultaneously changed. However, since the present system employs the single width-changing-rotation producing device and the rotation transmitting device transmits the rotation of the producing device to both the two drive shafts, the present system can be produced at low cost. The width-changing-rotation producing device may be replaced by a manually operable member such as a handle. In the last case, the drive force produced by the manually operable member may be transmitted by a drive-force transmitting device to both the two drive shafts. In the present system, the single width-changing-rotation producing device is commonly used by the carry-in and carry-out conveyors, and the CS conveying widths of the two conveyors are simultaneously changed.
(20) According to a twentieth feature of the present invention which includes any one of the seventeenth to nineteenth features (17) to (19), the width changing device further comprises a main-conveyor-side driven rotatable member which is provided for at least one of the main conveyors such that the main-conveyor-side driven rotatable member is rotatable about an axis line thereof, and is not movable in an axial direction thereof, relative to the at least one main conveyor; and a motion converting device which converts the rotation of the main-conveyor-side driven rotatable member into the movement of the movable side frame of the at least one main conveyor. It is possible to employ a driven rotatable member and a motion converting device for each of the main conveyors, and operate the respective motion converting devices in synchronism with each other for simultaneously moving the respective movable side frames of the main conveyors. Alternatively, it is possible to employ a rotatable member or no motion converting device for at least one of the main conveyors, and employ a connection member for connecting the movable side frame of the one main conveyor to that of another or the other main conveyor which has its driven rotatable member and motion converting device. The respective motion converting devices provided for the plurality of main conveyors may be synchronized with each other by controlling respective width-changing-:rotation producing devices exclusively provided for the main conveyors, respectively, or by transmitting the motion of one of the motion converting devices to the other motion converting device or devices.
(21) According to a twenty-first feature of the present invention which includes the twentieth feature (20), the width changing device further comprises a connecting member which connects the respective movable side frames of the main conveyors to each other so that the respective movable side frames of the main conveyors are movable as a unit.
(22) According to a twenty-second feature of the present invention which includes the twentieth or twenty-first feature (20) or (21), the rotation transmitting device transmits the rotation of the width-changing-rotation producing device to the main-conveyor-side driven rotatable member provided for the at least one main conveyor, in addition to the carry-in-conveyor-side drive shaft and the carry-out-conveyor-side drive shaft. It is possible to employ an exclusive width-changing-rotation producing device for rotating the driven rotatable member provided for at least one of the main conveyors, and employ a control device for automatically controlling, in addition to the common width-changing-rotation producing device for the carry-in and carry-out conveyors, the exclusive width-changing-rotation producing device for the one main conveyor, such that the CS conveying widths of the carry-in and carry-out conveyors and the main conveyor are simultaneously changed. However, since the present system uses the single width-changing-rotation producing device commonly for the carry-in and carry-out conveyors and the main conveyor, it can be produced at reduced cost. The present system may employ a single width-changing-rotation producing device commonly for all the main conveyors, or a plurality of width-changing-rotation producing devices for the plurality of main conveyors, respectively. In the case where the width-changing-rotation producing device provided for the carry-in and carry-out conveyors is replaced by a manually operable member such as a handle, the rotation transmitting device transmits the rotation produced by the manually operable member, to the driven rotatable member provided for at least one main conveyor, in addition to the two drive shafts provided for the carry-in and carry-out conveyors.
(23) According to a twenty-third feature of the present invention which includes any one of the fifth, seventh, eighth, and tenth to nineteenth features (5), (7), (8), and (10) to (19), each of the main conveyors, the carry-in conveyor, and the carry-out conveyors comprises a pair of side frames including at least one movable side frame which is movable toward, and away from, the other side frame, and wherein the system further comprises a width changing device which simultaneously changes a circuit-substrate conveying width defined by the pair of side frames of each of the carry-in conveyor and the carry-out conveyors, by moving the movable side frame of the each conveyor relative to the other side frame thereof; and a frame connecting device which connects, when the width changing device changes the respective circuit-substrate conveying widths of the carry-in and carry-out conveyors, the respective movable side frames of the main conveyors to the respective movable side frames of the carry-in and carry-out conveyors so that the respective movable side frames of the main conveyors and the carry-in and carry-out conveyors are movable as a unit. The frame connecting device may include a connection member which selectively takes one of an operative position where the connection member connects the respective movable side frames of the main conveyors to the respective movable side frames of the carry-in and carry-out conveyors, and an inoperative position where the connection member does not. The connection member may be one which is manually operable by an operator for being positioned at operator""s selected one of the operative and inoperative positions, or one which is driven by a connection-member driving device for being automatically positioned at one of the two positions.
(24) According to a twenty-fourth feature of the present invention which includes any one of the first to twenty-third features (1) to (23), each of the main conveyors and the at least one of the carry-in and carry-out conveyors comprises at least one conveyor belt which supports and conveys the circuit substrate, and where the main conveyors comprise a first belt-driving device which simultaneously drives the conveyor belts of the main conveyors, independent of the conveyor belt of the at least one of the carry-in and carry-out conveyors, and the at least one of the carry-in and carry-out conveyors comprises a second belt-driving device which drives the conveyor belt of the at least one of the carry-in and carry-out conveyors, independent of the conveyor belts of the main conveyors. Since the present system employs the exclusive belt-driving device for the main conveyors, and the exclusive belt-driving device for the at least one of the carry-in and carry-out conveyors, the conveyor belts of the main conveyors can be driven independent of the conveyor belts or belt of the carry-in and/or carry-out conveyors. Thus, the present system enjoys improved degree of freedom.
(25) According to a twenty-fifth feature of the present invention which includes any one of the fourth to twenty-fourth features (4) to (24), the component-holder positioning device comprises a plurality of rotary members which are rotatable about the common axis line of the component holders, independent of each other; and a rotary-motion applying device which applies a rotary motion to each of the rotary members such that the each rotary member is rotated while having a predetermined time difference from the preceding rotary member and that while the each rotary member is rotated by 360 degrees about the common axis line, the each rotary member is stopped at least one time, the rotary members having, at a common distance from the common axis line, respective holding portions each of which holds a corresponding one of the component holders such that the one component holder is movable in an axial direction thereof. Each of the rotary members may be equipped with a movable member which holds a corresponding one of the component holders and which is supported by the each rotary member such that the movable member is movable in a direction parallel to the axis line of the one component holder. In this case, each component holder is moved in the direction parallel to the axis line thereof, by the movement of the corresponding movable member. The holding portions may comprise respective holding holes in which the component holders are fitted such that the holders are rotatable about their axis lines. In this case, the current rotation position of the CC held by each holder can be changed, or the rotation-position error of the CC can be corrected. A holder revolving device including a plurality of rotary members which are rotatable about a common axis line, independent of each other, and which hold a plurality of component holders, respectively, is disclosed in U.S. patent application Ser. No. 08/769,700 assigned to the Assignee of the present U.S. Patent Application. The rotary-motion applying device may be one which includes a plurality of cam followers which are provided on the plurality of rotary members, respectively, and a rotary-motion applying cam device which sequentially engages the cam followers and moves them for rotating the corresponding rotary members about the common axis line. It is preferred that the rotary-motion applying cam device include a plurality of concave globoidal cams which are disposed at respective positions axis-symmetric with each other with respect to the common axis line such that lines of intersection of respective outer circumferential surfaces of the concave globoidal cams with a plane including respective axis lines of the concave globoidal cams and perpendicular to the common axis line cooperate to define a substantially continuous circle which has a center at the common axis line.
(26) According to a twenty-sixth feature of the present invention which includes any one of the fourth to twenty-fourth features (4) to (24), the component-holder positioning device comprises a rotatable body which is rotatable about the common axis line of the component holders and which has, at a common distance from the common axis line, a plurality of holding portions each of which holds a corresponding one of the component holders such that the one component holder is movable in an axial direction thereof. In this apparatus, too, the holding portions may comprise respective holding holes in which the component holders are fitted such that each of the component holders is rotatable about its axis line for changing the current rotation position of the CC held thereby, or correcting the rotation-position error of the CC. The rotatable body may be one which is rotatable by any desired angle in a positive direction or a reverse direction, or an intermittently rotatable body which is intermittently rotated by an intermittent-rotation angle which is equal to a regularly spacing angle at which the component holders are equiangularly spaced from each other about the common axis line. A drive source which rotates the rotatable body may be an exclusive one, or a common one which is shared by, e.g. an elevating and lowering device for elevating and lowering one or each component holder. In the case where the rotatable body is rotated by an exclusive drive source, the rotatable body can be rotated by any angle in either direction, which leads to improving the efficiency of transferring of CCs. In the case where the rotatable body is rotated by the common drive source, it is preferred to employ a motion converting device including a cain, a cam follower, etc., for transmitting the rotation of the drive source to the rotatable body. In this case, the total number of drive sources is decreased and accordingly the production cost of the present apparatus is reduced.
(27) According to a twenty-seventh feature of the present invention which includes the twenty-fifth or twenty-sixth feature (25) or (26), the common axis line of revolution of the component holders is perpendicular to the mounting-head moving plane, and wherein an axis line of each of the component holders extends parallel to the common axis line. The mounting-head moving plane in which the mounting head is moved may be either a horizontal plane, or a plane which is inclined with respect to a horizontal plane. In the case where the moving plane is inclined with respect to a horizontal plane, the respective axis lines of the component holders are inclined with respect to a vertical direction. Meanwhile, there is known a CC mounting system in which a CC supplying device which supplies CC, and/or a CS on which CCs are mounted are inclined with respect to a horizontal plane. In the latter case, the component holders inclined with respect to the vertical direction can receive the CCs from the CC supplying device and/or mount the CCs on the CS, while taking their attitudes perpendicular to the inclined CC supplying device and/or the inclined CS.
(28) According to a twenty-eighth feature of the present invention which includes the twenty-fifth or twenty-sixth feature (25) or (26), respective axis lines of the component holders are defined by a plurality of generators of a circular cone whose center line is defined by the common axis line of revolution of the component holders, and wherein the common axis line is inclined with respect to a perpendicular of the mounting-head moving plane, by an angle at which one of the generators is perpendicular to the mounting-head moving plane. In the case where the mounting-head moving plane is a horizontal plane, each of the component holders can take a vertical attitude at one of stop positions, and can be moved downward and upward at the one stop position. In the present system, the height position of each of the component holders in a direction parallel to the axis line of the each component holder can be changed as the rotatable body is rotated. Accordingly, an image pick-up device may be disposed in a space which is created below the component holders. The present system in which the axis line of the rotatable body is inclined can easily change the respective height positions of the component holders with a smaller number of parts than the case where each of the component holders is moved downward and upward by using a cam member which is provided above the locus of revolution of the holders and which has a lower cam surface including a height-changing portion, and cam followers which follows the cam surface of the cam member. Thus, the rotatable body enjoys a small mass, and can be rotated at high speed. In the case where the rotatable body is moved by a rotatable-body moving device, it can be moved at high speed. Thus, the efficiency of transferring of CCs can be improved.